1. Field of the Invention
The present invention relates to a data transmission apparatus for transmitting a data signal to a data receiver unit and a method of controlling data transmission with the data transmission amount self-controlled.
2. Description of the Background Art
When transmitting a data signal from a data transmission unit to a higher-level data receiver unit, the following requirement must be satisfied. That is, the maximum amount of data transmitted at a time is predetermined. In addition, the average amount of transmission data must not exceed a predetermined amount. The average transmission amount is calculated by dividing the total transmission amount by the number of transmission times. The amount of data transmitted at a time must be limited to satisfy the requirement.
Data is divided and transmitted multiple times to satisfy the requirement described above when the maximum amount of data transmitted at a time is predetermined and the average amount of data transmission must not exceed the predetermined amount. In this case, the problem is that, when fixed amount data is not always received at a constant rate, transmitting data in a predetermined average amount sometimes does not satisfy the requirement for the maximum amount of data that is transmitted at a time.
In addition, setting a maximum on the amount of data to be transmitted next based on the data transmission result puts a constraint on the transmission interval and prevents the efficient data transmission.